The present disclosure relates to non-volatile dual inline memory modules (NVDIMM-Ns), and more specifically, to conserving energy in NVDIMM-Ns.
NVDIMM-Ns are a type of non-volatile dual inline memory module that is byte-addressable and memory-mapped. NVDIMM-Ns are typically accessed by the memory controller at memory or near-memory speeds. NVDIMM-N-Ns may incorporate DRAM, flash memory, control logic and an independent power source to retain in-memory data through unexpected power loss events, such as system crashes or planned shutdowns. During normal operation, the NVDIMM-N appears to the host system as a DRAM memory module, providing the speed, latency and endurance benefits of DRAM. In the event of an unexpected power loss or system crash, the data residing in the DRAM is saved to flash memory. When power is returned, the in-memory state of the DRAM is restored from flash memory. For most NVDIMM-N solutions, the backup power to transfer the DRAM contents to flash is provided by supercapacitors or other backup power sources. For example, an NVDIMM-N plugs into a Joint Electron Device Engineering Council (JEDEC)-compliant dual inline memory module (DIMM) socket and operates as a DRAM DIMM during runtime. An NVDIMM-N will retain its data through a power loss event or system crash.
One main application of NVDIMM-N memory is to keep data persistent, in case of a power failure or catastrophic software and/or hardware failure. Capability to support data persistency often requires DRAM memory to be active, so that data can be copied from DRAM to flash, in case of power failure. Keeping all of the memory active may limit the data persistence because of backup power constraints. When memory (partially or fully) is not in use, conventional DRAM based memory consumes power to support refresh operation for data retention. Accordingly, it may be advantageous to provide systems and methods for conserving NVDIMM-N power for data continuity during a power failure or system crash.